Dr. Rhodes begins a fellowship in cardiothoracic surgery, only to have problems with his new boss. Dr. Choi is the new chief resident. Dr. Charles approaches Sarah with an interesting opportunity that catches her off-guard. April faces her recently discovered illness.

Dr. Manning and Dr. Rhodes separately treat complicated cases involving sick babies, only to uncover that the two cases could actually be intertwined. Elsewhere, Dr. Halstead and Dr. Charles treat a homeless man with an upbeat disposition who sheds some valuable insight that prompts one of the doctors to learn a thing or two along the way. Dr. Choi has a Navy corpsman follow him for the day as they deal with the toll of gang violence in the city, while Dr. Reese tries to understand the delicate balance required in her new position.

Dr. Manning and Jeff Clarke are forced to figure out a mystery illness when an Indonesian man who doesn't speak English arrives at the hospital in dire straights. Maggie takes Dr. Halstead to her family reunion. Dr. Rhodes takes on a complicated heart surgery without consulting Dr. Latham. Dr. Reese and Dr. Charles encounter a woman experiencing an unusual pregnancy.

Several patients are discovered to have the same rare infection, prompting Dr. Charles' daughter Robyn, an epidemiologist, to be brought in to find the common link. Dr. Choi and Dr. Rhodes work on an elderly man who is discovered to be very ill, but a conflict in how to best treat him develops between his son and his young girlfriend. Meanwhile, Dr. Reese tries to help a young drug addict and Maggie tends to a patient who is dear to her heart.

A car accident that occurs at the Chicago Marathon leaves a victim in critical condition and tests the mettle of Dr. Halstead, April and her fourth-year medical resident brother Noah, who must perform a difficult procedure in the field. A mother brings in her 8-year-old girl experiencing a sudden hearing loss and Dr. Manning is left to tend to the case, which takes a complicated turn. Dr. Choi deals with Olga, a woman who is malnourished, prompting him to bring in Dr. Charles to help assess the case. Meanwhile, Goodwin takes measures to get her personal life in order.

Dr. Manning tends to a young cancer patient and struggles to inform the parents of her dire condition. Elsewhere, Dr. Reese gets contacted by Danny, the troubled young man, and turns to Dr. Charles and Det. Lindsay for help in resolving a difficult situation. Goodwin and Maggie do their best to clear the logjam in the hospital and Dr. Rhodes fine-tunes his instincts after both Dr. Latham and Dr. Halstead pick up on things he doesn't. Meanwhile, a teenage science geek and her friends impress Dr. Choi and Natalie with their bio-engineering lab.

Sharon Goodwin's childhood sweetheart arrives at the hospital, but finds himself in dire straits. To help get his financial footing, Dr. Halstead gets lured into a concierge doctor app idea. Meanwhile, a young woman with a heart infection is treated by Dr. Rhodes against Dr. Charles' advice and Reese's former patient, a sex trafficking victim, reaches out to her for help.

Dr. Halstead and Dr. Manning deal with two warring brothers who are brought together when one finds himself in desperate need of a kidney. Dr. Reese's former patient Danny comes to a crossroad. Dr. Rhodes and Dr. Latham treat a 16-year-old girl with a genetic condition in need of surgery, but whose overprotective mother disagrees with that course of action. A convict with unusual intentions puts himself in the hospital and Dr. Charles meddles in his daughter Robyn's personal life, much to her dismay. Meanwhile, Dr. Halstead and April make a discovery that complicates her treatment for TB.

Goodwin tasks Dr. Charles with evaluating a patient as a possible heart recipient, while Jeff makes a confession to Dr. Manning. Dr. Choi deals with two MMA fighters who are brought into Chicago Med in bad shape. Elsewhere, Dr. Stohl returns to the hospital from his sabbatical leave and immediately offers up different medical opinion regarding the treatment of a patient under the care of Dr. Halstead. April discovers her TB medication may lead to further complications.

Dr. Rhodes and Dr. Charles' heart transplant patient gets into a car crash, revealing issues that could complicate her surgery. A past arrest causes trouble for Maggie when the arresting officer is brought to Chicago Med with a serious injury. Elsewhere, Dr. Manning and Dr. Halstead must defend their actions when explaining a patient's cause of death. Meanwhile, Dr. Halstead attempts to treat an uncooperative horse jockey.

It's a long night on the graveyard shift at Chicago Med, especially for Dr. Reese, who must deal with pronouncing patients dead on more than one occasion. April gets called in to work, much to the dismay of Tate, who pressures her to slow down. Meanwhile, Dr. Charles passes along some vital news to Dr. Latham, and Goodwin asks Dr. Rhodes to work on a most unusual patient.

Dr. Manning and Dr. Charles treat a teenage girl with a rapidly changing set of symptoms that has everyone perplexed. Dr. Choi and medical student Jeff Clark encounter a 19 year-old tough guy who is brought into the hospital in severe distress. Once they establish the cause of the pain, the situation quickly turns dangerous and a resolved Dr. Reese does her best to help. Dr. Halstead must deal with a difficult case that is further complicated by Dr. Stohl, who has a camera crew following him around to shoot a promotional video spotlighting the hospital.

Dr. Rhodes convinces Dr. Latham to join him for a medical trip out of town. Dr. Manning treats an 8 year-old cancer patient who wants to give up on his battle. Elsewhere, an unhealthy woman with heart problems is brought in and doesn't want to listen to doctors. Meanwhile, Dr. Choi, Dr. Charles and Dr. Reese work on a complicated case involving a woman with a personality disorder.

It's a miracle when a trauma patient survives the trip to the hospital, putting the pressure on Dr. Rhodes to keep the man alive. Dr. Choi and Dr. Manning have difficulty diagnosing the location of infection in a paralyzed patient. Dr. Reese must find purpose for a grieving widower who relies on a superhero costume. Meanwhile, April pushes Dr. Halstead to use unproved medications to help a patient with no other options.

Dr. Reese is contacted for help by a troubled teen in a psychiatric facility and Dr. Manning tries to help parents make a decision about their comatose daughter's surprise pregnancy. April begins to deal with repercussions from her personal life. Meanwhile, Dr. Choi and Dr. Rhodes work to save both a young girl from Ecuador who collapsed mid-flight, as well as her mother, who made great sacrifices for her daughter.

A suicide shakes the staff. Dr. Choi and Dr. Halstead face off over how to treat a patient with stroke symptoms. Family turmoil unfolds when a boy is treated after falling in a river. The importance of learning from mistakes is emphasized to Dr. Reese.

Will is troubled with a moral decision when his former teacher, Dr. Bella Rowan, is faced with a life-threating disease. Dr. Rhodes and Dr. Bardovi get involved in a sensitive situation when Rhodes disagrees with the father of a young patient regarding a risky procedure. Dr. Charles and Sarah handle an unusual case with a pilot that causes Sarah to have memories of Jason Wheeler's suicide. Maggie takes an aggressive approach to training a new nurse.

A hacker demanding a ransom payment shuts down the hospital computer system, forcing the doctors to diagnose patients without the aid of technology. A stressed Goodwin struggles to keep the hospital afloat when an unexpected visit from her ex-husband Bert and his new girlfriend make matters worse. Making use of his former navy experience, Dr. Choi and Noah have to locate a bullet inside a patient with a gunshot wound. Meanwhile, Sarah feels Dr. Charles may be trying to push her out and Robin's unusual behavior worries Dr. Rhodes.

Things get personal for Dr. Halstead when his unsupportive father is admitted to the hospital against his wishes. When treating Will's father, Dr. Rhodes reflects on his relationship with his dad. Dr. Charles gets involved when his daughter Robin's strange behavior continues to intensify and Dr. Choi struggles to help a teenage boy who is desperate to control his sexual urges. Dr. Manning feels the impact of being a working mother when a young boy is brought in for neglect. Meanwhile, Sarah teaches a group of high school students about the responsibilities of having a child by using fake baby dolls.

Dr. Rhodes fights to save a mother who's desperate to help her daughter beat cancer. Dr. Charles asks Sarah to conduct his daughter Robin's psych evaluation. When Will and Dr. Manning spend more time together at work, Nina goes to extreme measures to get Will's attention. Meanwhile, Dr. Choi puts pressure on Noah when a residency spot becomes available.

Dr. Rhodes challenges Dr. Charles and other hospital staff over the proper treatment for Robin. Dr. Manning seeks help from Det. Halstead when a sensitive case involving a young girl turns into a crime. Dr. Choi and April work together on a conflicting case. Meanwhile, Goodwin helps a friend in distress and, after eagerly awaiting, the doctors are surprised to learn who the new med resident is.

A new hotshot doctor arrives at Chicago Med causing competition for Dr. Rhodes, Dr. Halstead and Dr. Manning work together to diagnose a Syrian refugee without a medical record. When Robin is admitted back into the hospital for more complications, Dr. Reese takes a different approach to her treatment. Distracted from work because of Robin's worsening case, Dr. Charles is challenged by Goodwin and Noah hosts a graduation party that brings everyone together.